import { inject, injectable } from 'inversify';
import { CommandRegistry } from '@theia/core/lib/common/command';
import { MenuModelRegistry, MenuNode } from '@theia/core/lib/common/menu';
import { Disposable, DisposableCollection } from '@theia/core/lib/common/disposable';
import { BoardsServiceClientImpl } from './boards-service-client-impl';
import { Board, ConfigOption, Programmer } from '../../common/protocol';
import { FrontendApplicationContribution } from '@theia/core/lib/browser';
import { BoardsDataStore } from './boards-data-store';
import { MainMenuManager } from '../../common/main-menu-manager';
import { ArduinoMenus } from '../menu/arduino-menus';

@injectable()
export class BoardsDataMenuUpdater implements FrontendApplicationContribution {

    @inject(CommandRegistry)
    protected readonly commandRegistry: CommandRegistry;

    @inject(MenuModelRegistry)
    protected readonly menuRegistry: MenuModelRegistry;

    @inject(MainMenuManager)
    protected readonly mainMenuManager: MainMenuManager;

    @inject(BoardsDataStore)
    protected readonly boardsDataStore: BoardsDataStore;

    @inject(BoardsServiceClientImpl)
    protected readonly boardsServiceClient: BoardsServiceClientImpl;

    protected readonly toDisposeOnBoardChange = new DisposableCollection();

    onStart(): void {
        this.boardsDataStore.onChanged(() => this.updateMenuActions(this.boardsServiceClient.boardsConfig.selectedBoard));
        this.boardsServiceClient.onBoardsConfigChanged(({ selectedBoard }) => this.updateMenuActions(selectedBoard));
        this.updateMenuActions(this.boardsServiceClient.boardsConfig.selectedBoard);
    }

    protected async updateMenuActions(selectedBoard: Board | undefined): Promise<void> {
        if (selectedBoard) {
            this.toDisposeOnBoardChange.dispose();
            this.mainMenuManager.update();
            const { fqbn } = selectedBoard;
            if (fqbn) {
                const { configOptions, programmers, selectedProgrammer } = await this.boardsDataStore.getData(fqbn);
                if (configOptions.length) {
                    const boardsConfigMenuPath = [...ArduinoMenus.TOOLS, 'z01_boardsConfig']; // `z_` is for ordering.
                    for (const { label, option, values } of configOptions.sort(ConfigOption.LABEL_COMPARATOR)) {
                        const menuPath = [...boardsConfigMenuPath, `${option}`];
                        const commands = new Map<string, Disposable & { label: string }>()
                        for (const value of values) {
                            const id = `${fqbn}-${option}--${value.value}`;
                            const command = { id };
                            const selectedValue = value.value;
                            const handler = {
                                execute: () => this.boardsDataStore.selectConfigOption({ fqbn, option, selectedValue }),
                                isToggled: () => value.selected
                            };
                            commands.set(id, Object.assign(this.commandRegistry.registerCommand(command, handler), { label: value.label }));
                        }
                        this.menuRegistry.registerSubmenu(menuPath, label);
                        this.toDisposeOnBoardChange.pushAll([
                            ...commands.values(),
                            Disposable.create(() => this.unregisterSubmenu(menuPath)), // We cannot dispose submenu entries: https://github.com/eclipse-theia/theia/issues/7299
                            ...Array.from(commands.keys()).map((commandId, i) => {
                                const { label } = commands.get(commandId)!;
                                this.menuRegistry.registerMenuAction(menuPath, { commandId, order: `${i}`, label });
                                return Disposable.create(() => this.menuRegistry.unregisterMenuAction(commandId));
                            })
                        ]);
                    }
                }
                if (programmers.length) {
                    const programmersMenuPath = [...ArduinoMenus.TOOLS, 'z02_programmers'];
                    const label = selectedProgrammer ? `Programmer: "${selectedProgrammer.name}"` : 'Programmer'
                    this.menuRegistry.registerSubmenu(programmersMenuPath, label);
                    for (const programmer of programmers) {
                        const { id, name } = programmer;
                        const command = { id: `${fqbn}-programmer--${id}` };
                        const handler = {
                            execute: () => this.boardsDataStore.selectProgrammer({ fqbn, selectedProgrammer: programmer }),
                            isToggled: () => Programmer.equals(programmer, selectedProgrammer)
                        };
                        this.menuRegistry.registerMenuAction(programmersMenuPath, { commandId: command.id, label: name });
                        this.toDisposeOnBoardChange.pushAll([
                            this.commandRegistry.registerCommand(command, handler),
                            Disposable.create(() => this.unregisterSubmenu(programmersMenuPath)),
                            Disposable.create(() => this.menuRegistry.unregisterMenuAction(command, programmersMenuPath))
                        ]);
                    }
                }
                this.mainMenuManager.update();
            }
        }
    }

    protected unregisterSubmenu(menuPath: string[]): void {
        if (menuPath.length < 2) {
            throw new Error(`Expected at least two item as a menu-path. Got ${JSON.stringify(menuPath)} instead.`);
        }
        const toRemove = menuPath[menuPath.length - 1];
        const parentMenuPath = menuPath.slice(0, menuPath.length - 1);
        // This is unsafe. Calling `getMenu` with a non-existing menu-path will result in a new menu creation.
        // https://github.com/eclipse-theia/theia/issues/7300
        const parent = this.menuRegistry.getMenu(parentMenuPath);
        const index = parent.children.findIndex(({ id }) => id === toRemove);
        if (index === -1) {
            throw new Error(`Could not find menu with menu-path: ${JSON.stringify(menuPath)}.`);
        }
        (parent.children as Array<MenuNode>).splice(index, 1);
    }

}